To import geometry objects from a file or from another geometry, in the Geometry toolbar, click Import (). You can also right-click the Geometry node to add this node from the context menu. Then enter the properties of the import feature in the Import section of the Settings window for the Import node.

In the Source list choose the type of data to import: Any importable file and COMSOL Multiphysics file are always available. If there is another geometry sequence of the same dimension in the model, the type Geometry sequence is available. In addition, you can choose Mesh in 1D; DXF file and Mesh in 2D; and Mesh or 3D printing file (STL, 3MF, PLY) in 3D. When choosing Mesh or Mesh or 3D printing file (STL, 3MF, PLY), you can import the geometry defined by a mesh of any meshing sequence, of the same space dimension, or a mesh file in the COMSOL Multiphysics format. In 3D, it is also possible to import a mesh defined by an STL, 3MF, or PLY file as a geometry. These files, which represent 3D surface meshes and are often used for 3D printing and additive manufacturing, can be used as a basis for creating a volumetric mesh for a single geometry domain. In addition, files with a NASTRAN, VRML (3D only), or sectionwise format are supported.

In 2D and 3D (but not in work planes, where virtual operations are always excluded), when COMSOL Multiphysics file is selected from the Source list, the Include result from virtual operations check box is selected by default. Clear that check box if you want to exclude the virtual operations in the file when importing it into another geometry.

In all cases, you need to specify the geometry sequence, mesh, or file to import. Then click Import to bring in the geometry or mesh to use as a part of the geometry in the geometry sequence.

For the Any importable file and COMSOL Multiphysics file source types (and the 3D CAD and ECAD file source types), specify the filename in the Filename field or click the Browse button.

For import from another geometry sequence, select the geometry sequence or meshing sequence from the Geometry list below.

For import of a mesh, choose one of the available meshing sequences (from other model components of the same dimension) or mesh parts from the Mesh list. Use the Go to Source button () to move focus to the meshing sequence or mesh part that you selected. If you choose None, you can click Browse to locate a mesh or STL file or specify it in the Filename field. If you import an STL or NASTRAN file, for example, clicking Import also creates a Mesh Part node of the same dimension as the geometry component with an Import subnode under Global Definitions to make it easy to reuse the imported mesh as a geometry part. See Import for additional settings that you can make for the import in the mesh part and Using Mesh Parts for more information about mesh parts.

For DXF, mesh and 3D printing file formats, and 3D CAD import, you can change a number of properties when you have selected the file type. To import the file, click the Import button (). If you have changed some property, the software automatically re-imports the file when you click a build button. If you have changed the source file, you need to explicitly click the Import button to read the modified file.

When you have selected a mesh or 3D printing file, you can optionally simplify the mesh before creating the geometry. The simplification can remove small defects typically present in mesh data from measurements, such as tomography, and it can speed up geometry processing by removing unnecessary elements from all kind of meshes. Select the Simplify mesh check box to enable simplification.

The Relative simplification tolerance is relative to the dimensions of the entire geometry and specifies a global limit for how much the mesh can be modified. The Defect removal factor is relative to the local feature size, as estimated by the algorithm, and is combined with the global limit to produce a limit for how much the mesh can be modified at a certain location. If the mesh contains many defects that you want to remove, you could try to increase the value of the Defect removal factor. If the mesh describes the desired geometry with high accuracy, you may want to decrease this factor instead.

The Form solids from surface objects check box is selected by default to create solid geometry objects from surface mesh objects from, for example, an STL file. If you do not want or need solid geometry objects, clear this check box.

In the Layer selection list, select the layers to import.

Under Import options, select Form solids to unite and convert all objects in each layer to a solid object, select Knit curves to unite and convert all objects in each layer to a curve object, or select Do not knit to do nothing.

If the Repair imported objects check box is selected, enter a Relative repair tolerance. To create a geometry for mesh generation and finite element analysis, COMSOL Multiphysics requires a high degree of accuracy within the CAD drawing. Sometimes DXF geometries contain small gaps and exceedingly short edges that make it impossible to create a valid 2D solid or a valid mesh. COMSOL Multiphysics provides repair tolerance settings to remove short edges and close small gaps during DXF file import. The absolute repair tolerance is the relative repair tolerance times the maximum coordinate of the imported objects (the default value is 10−5). Geometric entities that have a distance less than the absolute repair tolerance are merged.

Select the Resulting objects selection check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the objects consist of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option from the Show in physics (Show in instances if in a geometry part; Show in 3D in a plane geometry under a work plane in a 3D component) list: All levels, Domain selection, Boundary selection, Edge selection, or Point selection. The default is Domain selection, which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose Boundary selection. These selections do not appear as separate selection nodes in the model tree. Select Off to not make any selection available outside of the geometry sequence. From the Color list, choose a color for highlighting the resulting objects selection. See Selection Colors.

Select the Individual objects selections check box to create predefined selections (for all levels — objects, domains, boundaries, edges, and points — that are applicable) in subsequent nodes in the geometry sequence for each individual object in the geometry file and for each relevant entity level. To also make all or one of the types of resulting entities (domains, boundaries, edges, and points) that the objects consist of available as selections in all applicable selection lists (in physics and materials settings, for example), choose an option from the Show in physics (Show in instances if in a geometry part) list: All levels, Domain selection, Boundary selection, Edge selection, or Point selection. The default is Domain selection, if available, which is suitable for use with materials and physics defined in domains. For use with a boundary condition, for example, choose Boundary selection. These selections do not appear as separate selection nodes in the model tree. Select Off to not make any selection available outside of the geometry sequence.

If you want to make the resulting entities contribute to a cumulative selection, select a cumulative selection from the Contribute to list (the default, None, gives no contribution), or click the New button to create a new cumulative selection (see Cumulative Selections).